By John R. Platt | November 5, 2014
The views expressed are those of the author and are not necessarily those of Scientific American.
Fifty birds flew home last month. Now, 50 may not seem like much and flight might not sound all that unusual for birds, but we’re talking about the critically endangered rowi (Apteryx rowi), New Zealand’s scarcest kiwi species and one of the world’s rarest flightless birds.
Rowi have had a rough time in the wild. Invasive predators such as European stoats (Mustela erminea) and domesticated cats and dogs nearly wiped the species out in their sole habitat, the Ōkārito forest on New Zealand’s South Island. The remaining birds lay about 80 eggs a year, only 40 of which hatch. Of those 40, four manage to survive predators long enough to reach six months of age. On average, just two wild rowi make it to adulthood every year. After that they are usually safe, but a 5 percent survival rate is not a good start.
That’s where the New Zealand Department of Conservation (DOC) comes in. A few years ago the DOC started removing eggs from the wild, hatching them in a nearby nursery and then flying them hundreds of kilometers away to a secure facility where predators could not reach them. The point of the Operation Nest Egg program is less to hatch new birds than to let them grow up in safety until they are large enough to defend themselves. At about one kilogram, adult rowi are actually pretty tough and can easily counter predators with their sharp beaks and claws.